Certain thiazolotriazolyphosphonothioates used as insecticides

ABSTRACT

A compound represented by the formula ##SPC1## 
     Wherein 
     R 1  and R 2  are lower alkyl having six or less carbon atoms, 
     X is bromine is used to combat phylophogous insects.

This is a division of application Ser. No. 319,490, filed Dec. 29, 1972,now U.S. Pat. No. 3,904,639.

This invention relates to novel thiazolotriazolylphosphonothioates andto a process for the preparation of the same. Further, the inventionrelates to insecticidal and acaricidal compositions containing one ormore of said novel compounds and further includes methods for combattinginsects and mites with these compounds.

A number of organo phosphate insecticides have been used for the controlof many injurious insects and certain materials are known to beeffective. However, many of these systemic insecticides have astrongtoxicity for human and warm-blooded animals.

Among harmful insects are, phytophagous mites which give great damage toplants and crops. Indeed a crop free from mite damage can scarcely befound. The damage is very large and considerable money for exterminationexpense is spent annually. Further, some insects and mites havingresistance against the currently employed insecticides and acaricideshave recently appeared. Therefore, it becomes a matter of importance tocontrol the insects and the mites. Accordingly, development of novel,effective insecticides and acaricides is desired in order to controlthese insects and mites.

The inventors have discovered that the compounds of this invention havesuperior insecticidal and acaricidal activities.

The novel compounds of this invention are characterized by the followingformula: ##SPC2##

Wherein

R₁ and R₂ are lower alkyl having six or less carbon atoms,

X is bromine.

It is one object of the present invention to provide newthiazolotriazolylphosphonothioates, which are useful in the control ofinsects and mites. It is another object of the present invention thatthe compounds of the invention have sufficient low phyto-toxicity sothat they can be used to without any injury to living plants and toprovide agents having extremely low mammal toxicity.

In the Japanese Patent Publication No. 30192/1971 it has been shown that0,0-dialkyl-2-thiazolo[3,2-b]-s-triazolylthionophosphates having nosubstituent at 6 position therein are useful as insecticidal andacaricidal compositions.

But the inventors herein synthesized variousthiazolotriazolylphosphonothioates and tested the biological activitythereof, and have discovered that thiazolotriazolylphosphonothioateshaving at the 6 position a bromine substituent have strong insecticidaland acaricidal activities and furthermore, these compounds have very lowmammal toxicity.

For example, acute oral toxicity LD₅₀ (mouse) of0,0-diethyl-2-(5-methylthiazolo[3,2-b]-s-triazolyl)thionophosphates ofJapanese Patent Publication No. 30192/1971 is 33-50 mg/kg, but one of0,0-diethyl-2-(5-methyl-6-bromothiazolo[3,2-b]-s-triazolyl)thionophosphateof the present invention is 150 mg/kg, so that it can be said to becomparatively safe.

The compounds of this invention can be prepared in accordance with thefollowing equation: ##SPC3##

(wherein R₁, R₂ and X represent the herein after described meanings.)

Usually the process of the invention is carried out in a proper inertsolvent by the use of alkali condensing agents. As an inert solvent,acetone, dioxane, acetonitrile and pyridine have been employed. Usingthese inert solvents, the compounds of this invention are obtained inlow yields such as 5 to 6%.

However, the inventors have discovered that the compounds of thisinvention are be obtained in satisfactory high yields such as 50 to 70%when dimethylformamide or dimethylsufoxide are employed as solvents inthe presence of potassium carbonate or sodium carbonate as condensingagents.

In a practical method, the compounds of this invention are preparedthrough the reaction of 0,0-dialkylthiophosphorylchloride with6-halogenothiazolo[3,2-b]-s-triazol using dimethylformamide ordimethylsulfoxide as a solvent in the presence of alkali carbonate as acondensing agent, or with alkali metal salts of6-halogenothiazolo[3,2-b]-s-triazol which are dissolved in the solventsuch as dimethylformamide or dimethylsulfoxide.

Reaction temperature is 40° - 60°C, preferably 45° - 50°C and thereaction terminates after 4 and 10 hours.

After the reaction is terminated, the products are isolated from thereaction mixture by employing the following treatment.

The reaction mixture is poured into water after cooling to roomtemperature, this water mixture is alkalized by adding dilute sodiumhydroxide solution and unreacted starting materials are dissolved in thealkali solution. The crystallized material was collected by filtration,washed with water and dried, and the crude product is obtained as acrystal.

The crude product can be purified by recrystallizing from a mixture ofligroin and petroleum ether.

The desired product is obtained as white crystal.

Unreacted starting material can be recovered from the mother liquor andacidified with hydrochloric acid solution.

In order to facilitate a clear understanding or the invention, thefollowing preferred specific embodiments are described as illustrativeexamples and not as limiting the invention.

EXAMPLE 1.0,0-Dimethyl-2-(5-methyl-6-bromothiazolo[3,2-b]-s-triazolyl)thionophosphate

4.68 g of 2-hydroxy-5-methyl-6-bromothiazolo[3,2-b]-s-triazole, 3 g ofpotassium carbonate and 3 g of 0,0-dimethylthiophosphoryl chloride weredissolved in 100 ml of dimethylformamide and heated at 45° - 50°C for 4hours under agitation. Then the reaction mixture was poured into waterand alkalized sodium hydroxide solution to crystallize the reactionproduct. The crystallized material was gathered by filtration, washedwith water and dried. The dried crystal was recrystallized from mixedsolvent of ligroin and petroleum ether and 4.1 g of white crystal havinga melting point of 100° - 102°C were obtained. The crystal consist of0,0-dimethyl-2-(5-methyl-6-bromothiazolo[3,2-b]-s-triazolyl)thionophosphate,and the elemental analysis was as follows: Found (%); C, 23.41; H, 2.55;N, 11.95; S, 17.64; Calcd. for C₇ H₉ BrN₃ O₃ PS₂ (%); C, 23.47; H, 2.53;N, 11.73; S, 17.90.

EXAMPLE 2.0,0-Diethyl-2-(5-methyl-6-bromothiozolo[3,2-b]-s-triazoly)thionophosphate

4.86 g of 2-hydroxy-5-methyl-6-bromothiazolo[3,2-b]-s-triazole, 3 g ofpotassium carbonate and 3.4 g of 0,0-diethylthiophosphoryl chloride weredissolved in 100 ml of dimethylformamide and heated at 45° - 50°C for 4hours under agitation.

By a procedure similar to Example 1, 5 g of0,0-diethyl-2-(5-methyl-6-bromothiazolo[3,2-b]-s-triazolyl)thionophosphatehaving a melting point of 102° - 103°C were obtained. Elemental analysiswas as follows: Found (%); C, 27.83; H, 3.47; N, 11.11; S, 16.22; Calcd.for C₉ H₁₃ BrN₃ O₃ PS.sub. 2 (%); C, 27.99; H, 3.39; N, 10.88; S, 16.60.

EXAMPLE 3.0,0-Dimethyl-2-(5-methyl-6-chlorothiazolo[3,2-b]-s-triazolyl)thionophosphate

3.79 g of 2-hydroxy-5-methyl-6-chlorothiazolo[3,2-b]-s-triazole, 3 g ofpotassium carbonate and 3 g of 0,0-dimethylthiophosphoryl chloride weredissolved in 100 ml of dimethylformamide and heated at 45° - 50°C for 4hours under agitation.

By a procedure similar to Example 1, 3.4 g of0,0-dimethyl-2-(5-methyl-6-chlorothiazolo[3,2-b]-s-triazolyl)thionophosphatehaving a melting point of 73° - 75°C were obtained. Elemental analysiswas as follows: Found (%) ; C, 26.71 ; H, 2.94 ; N, 13.67 ; S, 20.34 ;Calcd. for C₇ H₉ ClN₃ O₃ PS₂ (%) ; C, 26.80 ; H, 2.89; N, 13.39 ; S,20.44.

EXAMPLE 4.0,0-Diethyl-2-(5-methyl-6-chlorothiazolo[3,2-b]-s-triazolyl)thionophosphate

3.79 g of 2-hydroxy-5-methyl-6-chlorothiazolo[3,2-b]-s-triazole, 3 g ofpotassium carbonate and 0,0-diethylthiophosphoryl chloride weredissolved in 100 ml of dimethylformamide and 3.4 g heated at 45° - 50°Cfor 4 hours under agitation.

By a procedure similar to Example 1, 4.5 g of0,0-diethyl-2-(5-methyl-6-chlorothiazolo[3,2-b]-s-triazolyl)thionophosphatehaving a melting point of 80° - 82°C were obtained. Elemental analysiswas as follows: Found (%) ; C, 31.54 ; H, 3.78 ; N, 12.76 ; S, 18.54 ;Calcd. for C₉ H₁₃ ClN₃ PS₂ (%) ; C, 31,63 ; H, 3.83 ; N, 12.30 ; S,18.76.

In addition to the above mentioned compound described in the precedingexamples, some typical compounds of the present invention are listed inTable I.

                  Table I                                                         ______________________________________                                         ##STR1##                                                                     Compound No.                                                                              R.sub.1  R.sub.2  X     m.p. (°C)                          ______________________________________                                        I           CH.sub.3 CH.sub.3 Br    100 - 102                                 II          C.sub.2 H.sub.5                                                                        C.sub.2 H.sub.5                                                                        Br    102 - 103                                 III         CH.sub.3 CH.sub.3 Cl    73 - 75                                   IV          C.sub.2 H.sub.5                                                                        C.sub.2 H.sub.5                                                                        Cl    80 - 82                                   V           CH.sub.3 C.sub.2 H.sub.5                                                                        Br    93 - 95                                   ______________________________________                                    

Hereinafter, the compounds of this invention are represented by CompoundNo. in Table 1.

The method of the present invention comprehends the employment of aliquid or solid composition containing one or more of the presentcompounds as an active component.

The compound can be used directly without mixing with suitable carriers.

The active ingredient of this invention may be formulated by mixing withsuitable carriers in a form generally used in pesticidal compositionsuch as wettable powder, emulsifiable concentrate, dust formulation,granular formulation, water soluble powder and aerosol. As solidcarriers, bentonite, diatomaceous earth, apatite, gypsum, talc,pyrophyllite, vermiculite, clay and others are used. As liquid carriers,kerosene, mineral oil, petroleum, solvent naphtha, xylene, cyclohexane,cyclohexanone, dimethylformamide, dimethylsulfoxide, alcohol, acetone,benzene and others are used. Sometimes surface active agent is added inorder to give a homogeneous and stable formulation.

Furthermore, the composition may be applied as a mixture with otherfungicides, insecticides, acaricides, plant growth regulators andfertilizers.

The concentrations of the active ingredients in the insecticidal andacaricidal compositions of this invention vary according to type offormulation, and they are, for example, used in a range of 5 - 80 weightpercent, preferably 20 - 80 weight percent, in wettable powders, 5 - 70weight percent, preferably 10 - 50 weight percent, in emulsifiableconcentrates, and 0.5 - 20 weight percent, preferably 1 - 10 weightpercent in dust formulations.

The non-limiting examples for the insecticidal and acaricidalcompositions are illustrated as follows:

EXAMPLE 5. Wettable Powder

                        Parts by weight                                           Compound I          40                                                        Higher alcohol sulfonate ester                                                                    5                                                         Diatomaceous earth  51                                                        White carbon        4                                                     

These are mixed homogeneously and micronized to fine particles.Consequently, wettable powder containing 40 % of active ingredient isobtained. In practical use, it is diluted to a certain concentrationwith water and is sprayed as a suspension.

EXAMPLE 6. Emulsifiable Concentrate

                        Parts by weight                                           Compound II         30                                                        xylene              40                                                        dimethylformamide   22                                                        polyoxyethylene alkylarylether                                                                     8                                                    

These are mixed and dissolved.

Consequently, emulsifiable concentrate containing 30% of the activeingredient is obtained. In practical use, it is diluted to certainconcentration with water and then is sprayed as an emulsion.

EXAMPLE 7 Dust Formulation

                       Parts by weight                                            Compound III        3                                                         Talc               97                                                     

These are mixed homogeneously and micronized to fine particles.Consequently, dust formulation containing 3% of the active ingredient isobtained. In practical use it is directly applied.

In the Example 5 - 7, it is not intended to limit the emulsifying,wetting or dispersing agents, carriers and solvents to the onesdescribed by way of illustration.

The compounds listed in Table 1 possess very superior insecticidal andacaricidal activities compared to known compounds.

The superior insecticidal and acaricidal effects of the novel compoundsof this invention are clearly illustrated by the following tests.

In these all tests,0,0-dimethyl-2-(5-methylthiazolo[3.2-b]-s-triazolyl)thionophosphate ofthe Japanese Patent Publication No. 30192/1971 is compared with thecompounds of this invention.

TEST 1. Insecticidal Activity Against Fly

Fixed concentration of acetone solution containing test compound wereprepared.

20 house flies (Musca domestica Linne) were tested with 1 μ l of acetonesolution at their thoracic dosial by microsyringe and kept at atemperature of 25°C and at a humidity of 65%. 24 hours and 48 hoursafter treatment, dead flies were counted and mortality (%) wascalculated. The results were shown in Table 2.

                  Table 2                                                         ______________________________________                                        Test    *Contrast Active compound 1/1 fly                                                             active compound 0.5/1 fly                             Compound                                                                              24 hrs.   48 hrs.   24 hrs. 8 hrs.                                    ______________________________________                                        I       100       100       95      100                                       II      100       100       90      100                                       III     100       100       90       95                                       IV      100       100       90      100                                       V       100       100       90      100                                       Contrast*                                                                             100       100       70       70                                       ______________________________________                                         *Contrast :                                                                   0,O-dimethyl-2-(5-methylthiazolo[3,2-b]-s-triazolyl)thionophosphate      

TEST 2. Insecticidal Activity Against Cockroach

Acetone solution of test compound were dropped on filter paper having adiameter of 9cm in order that active compound on filter paper became 125and 31.3mg/m². The filter paper was airdried and setted in schale, andin which 10 hatched nymph (American cockroach, Periplaneta americanaLinne) were inoculated.

24 hours and 72 hours after inoculation, dead insects were counted andmortality (%) was calculated.

The results were shown in Table 3.

                  Table 3                                                         ______________________________________                                                Active compound  Active compound                                      Test    125 mg/m.sup.2   31.3 mg/m.sup.2                                      Compound                                                                              24 hrs.    72 hrs.   24 hrs. 72 hrs.                                  ______________________________________                                        I       100        100        30     100                                      II      100        100       100     100                                      III     100        100        40     100                                      IV      100        100       100     100                                      V       100        100       100     100                                      Contrast*                                                                             100        100        0       30                                      ______________________________________                                    

TEST 3. Insecticidal Activity Against Mosquito

An aqueous suspension of wettable powder formulated in similar manner toExample 5 were poured in 200 ml beaker and in which 20 Japanese cellermosquito (Culex pipiens pallens Coqvii Maskell) were inoculated. 24hours and 48 hours after inoculation, dead mosquitos were counted andmortality (%) were calculated.

The results were shown in Table 4.

                  Table 4                                                         ______________________________________                                        Conc. of Active                                                                           Test Com-                                                         Ingredient  pound No. II  Contrast*                                           (ppm)       24 hrs.  48 hrs.  24 hrs.                                                                              48 hrs.                                  ______________________________________                                        0.0833                        100    100                                      0.0417                        10     100                                      0.0209                        0       30                                      0.0105                        0       0                                       0.0083                                                                        0.0067      100      100                                                      0.0042      100      100                                                      0.0021       95      100                                                      0.0011       15       90                                                      ______________________________________                                    

TEST 4. Insecticidal Activity Against Aphid

A potted chrysanthemum which Chrysanthemum aphid (Macrosiphoniellasanborni Gillette) infestation and a potted apple which Woolly appleaphid (Eriosoma lanigerum Hausmann) infestation were used.

An aqueous suspension of wettable powder formulated in similar manner toExample 5 were sprayed. After a fixed number of days from spraying, thestate of the Aphid was observed and estimated according to followinggrading.

- : no effect

+ : weak effect

++ : considerable effect

+++ : nearly perfect effect

The results were shown in Table 5.

                  Table 5                                                         ______________________________________                                                 Chrysanthemum aphid                                                                           Woolly apple aphid                                            (Conc. of Active                                                                              (Conc. of Active                                     Test     Ingredient 100 ppm)                                                                           Ingredient 500 ppm)                                  Compound 7 days    10 days   7 days  10 days                                  ______________________________________                                        I        +++       +++       +++     +++                                      II       +++       +++       +++     +++                                      III      +++       +++       +++     +++                                      IV       +++       +++       +++     +++                                      V        +++       +++       +++     +++                                      Contrast*                                                                              +++       +++        ++     +++                                      ______________________________________                                    

TEST 5 Insecticidal Activity Against Cabbage Armyworm

10 Multigeneration breeded armyworms (Leucania separata Walker) wereused for this test.

A leaf of corn plant was dipped in an aqueous emulsion of emulsifiableconcentrate formulated in similar manner to Example 6 for 30 seconds andair dried. Then the leaf was placed on filter paper having 9 cm diameteron a scale. The test insects were inoculated into the scale and thescale was put on the cover. After 1 day and 3 days from inoculation,dead insects were counted and mortality (%) were calculated. The resultswere shown in Table 6.

                                      Table 6                                     __________________________________________________________________________           Concentra-                                                                            Concentra-                                                                            Concentra-                                                                            Concentra-                                            tion    tion    tion    tion                                           Test   62.5 ppm                                                                              31.3 ppm                                                                              15.7 ppm                                                                              7.8 ppm                                        Compound                                                                             1 day                                                                             3 days                                                                            1 day                                                                             3 days                                                                            1 day                                                                             3 days                                                                            1 day                                                                             3 days                                     __________________________________________________________________________    I      100 100 100 100 90  100 60  100                                        II     100 100 100 100 100 100 80   90                                        III    100 100 100 100 80  100 50   90                                        IV     100 100  90 100 80  100 50   90                                        V      100 100 100 100 90  100 70  100                                        Contrast*                                                                             90 100  70 100 30   80  0   0                                         __________________________________________________________________________

TEST 6. Test for Control of Mite

About 30 adult female mites of desert spider mite (Tetranychusdesertorum Banks) laid on main leaves of the potted kidney bean plantsgrown 7 and 10 days stage after sprouting. One day later, the woundedmites were removed from the plants. The compounds to be tested weresprayed on the plants as water suspension of emulsifiable concentrateprepared by the method of Example 6. After 1 day and 3 days fromspraying, dead mites was counted and mortality (%) was calculated.

Rating of mortality was recorded as follows:

    Mortality                Rating                                               ______________________________________                                        100 %                    +++                                                  99 - 90 %                ++                                                   89 - 50 %                +                                                    50 - 0 %                 -                                                    ______________________________________                                    

The results are shown in Table 7.

                  Table 7                                                         ______________________________________                                               Concentration of Active Ingredient                                     Test     125 ppm     31.3 ppm    7.81 ppm                                     Compound 1 day   3 days  1 day 3 days                                                                              1 day 3 days                             ______________________________________                                        1        +++             +++         +++                                      II       +++             +++         +++                                      III      +++             +++         +++                                      IV       +++             +++         +++                                      V        +++             +++         +++                                      Contrast*                                                                              +++             +++          ++   +++                                ______________________________________                                    

We claim:
 1. A method of preventing injury to plants by phytophagousinsects comprising applying to the plants to be protected aninsecticidally effective amount of a compound represented by theformula: ##SPC4##in which R₁ and R₂ are each methyl or ethyl.
 2. Themethod of claim 1 in which a composition is applied to said plantscontaining said compound and a carrier.
 3. The method of claim 2 inwhich said carrier is selected from the group consisting of solidcarriers and liquid carriers, said solid carriers being selected fromthe group consisting of bentonite, diatomaceous earth, apatite, gypsum,talc, pyrophyllite, vermiculite, and clay, said liquid carriers beingselected from the group consisting of kerosene, mineral oil, petroleum,solvent naphtha, xylene, cyclohexane, cyclohexanone, dimethylformamide,dimethylsufoxide, alcohol, acetone, and benzene.
 4. The method of claim3 in which said composition is in the form of a wettable powder and theconcentration of active ingredient in said wettable powder is from 5 to80 weight percent.
 5. The method claim 3 in which said composition is inthe form of an emulsifiable concentrate and the concentration of activeingredient in said emulsifiable concentrate is from 5 to 70 weightpercent.
 6. The method of claim 3 in which said composition is in theform of a dust formulation and the concentration of active ingredient insaid dust formulation is from 0.5 to 20 weight percent.